Licensed yellow taxis wait at Exit 3 of the Arrivals level. Pre-booked taxis have a separate waiting area near the terminal.
Kalamaki (Alimos) is outside the fixed-fare city-centre zone, so the fare is charged on the meter. The ride takes about 40 minutes.
FREENOW, Uber and Bolt all work in Athens and all of them send licensed taxis – useful for getting around between the venue, your hotel and the city.